RESIDUAL-STRESS IN SOME ELASTOPLASTIC PROBLEMS OF ROLLING-CONTACT WITH FRICTION

The problem or rolling contact is of a great interest from the practic al and cognitive points of view. It concerns for example a wheel passa ge on a rail, as well as many other processes where rolling or rolling with sliding is involved. Particularly, residual stresses distributio ns in the subsurface area due to plastic deformations are of significa nt importance: these stresses strongly influence fatigue limit and cra cking tendencies of the material. A motion of the wheel on the rail (o r of a roller on a strip) often has a very complex character: it consi sts of rolling, sliding in the longitudinal direction due to brakings and accelerations, sliding in the transversal direction, etc. Investig ations conducted on this field by many authors have not yet delivered a unique solution. The aim of this paper is to determine the influence of some of these components of the wheel motion (separately and in co mmon action) on residual stresses distributions. The problem has been investigated numerically by the FEM method, using the program SEGLA de veloped by the authors. The program can be applied to solving linear a nd nonlinear 2D, axisymmetric and 3D problems with elasto-plastic effe cts in the nonlinear contact and fracture mechanics. It uses three, fo ur, six, eight and nine- node elements and also the special ''spring'' elements to model contact. The applied algorithm allows automatic ana lysis of these fragments of boundary, which enter and leave the contac t; in the area where the ''new'' contact is created the program introd uces additional elements. Copyright (C) 1996 Elsevier Science Ltd.